implemented recursive dedupe and compile

internal/plugin/interface.go

@@ -60,6 +60,10 @@ func compileSource(source data.Source) (data.Source, error) {
 	}
 
 	// find what object this source corresponds to
+	if source.ObjectType != "" {
+		return source, nil
+	}
+
 	sourceType := source.SourceType
 
 	if sourceType.RegexSong.MatchString(source.Url) {
@@ -80,7 +84,24 @@ func compileSource(source data.Source) (data.Source, error) {
 	return source, errors.New("couldn't find corresponding object source on " + sourceType.Name + " for " + source.Url)
 }
 
+func dedupeSources(sources []data.Source) []data.Source {
+	urls := map[string]interface{}{}
+	deduped := []data.Source{}
+
+	for _, raw := range sources {
+		parsed, _ := compileSource(raw)
+
+		if _, u := urls[parsed.Url]; !u {
+			urls[parsed.Url] = true
+			deduped = append(deduped, parsed)
+		}
+	}
+
+	return deduped
+}
+
 func Fetch(source data.Source) (data.MusicObject, error) {
+	// the fetch function without the post processing of the music objects
 	source, err := compileSource(source)
 	if err != nil {
 		return nil, err
@@ -92,15 +113,33 @@ func Fetch(source data.Source) (data.MusicObject, error) {
 	}
 
 	if source.ObjectType == data.SongSource {
-		return plugin.FetchSong(source)
+		song, err := plugin.FetchSong(source)
+
+		if err != nil {
+			return song, err
+		}
+		song.Sources = dedupeSources(append(song.Sources, source))
+		return song, nil
 	}
 
 	if source.ObjectType == data.AlbumSource {
-		return plugin.FetchAlbum(source)
+		album, err := plugin.FetchAlbum(source)
+
+		if err != nil {
+			return album, err
+		}
+		album.Sources = dedupeSources(append(album.Sources, source))
+		return album, nil
 	}
 
 	if source.ObjectType == data.ArtistSource {
-		return plugin.FetchArtist(source)
+		artist, err := plugin.FetchArtist(source)
+
+		if err != nil {
+			return artist, err
+		}
+		artist.Sources = dedupeSources(append(artist.Sources, source))
+		return artist, nil
 	}
 
 	return nil, nil